年老褐煤水解制备腐植酸及特性分析

Preparation and Characterization Analysis of Humic Acids by Hydrolysis of Aged Lignite

以NaOH为催化剂,通过水解反应降解年老褐煤的大分子结构来制备再生腐植酸,考察了反应温度、NaOH质量浓度、反应时间和水(体积)煤(质量)比对腐植酸收率的影响,结果表明,通过优化水解反应条件可使腐植酸收率由11.25%提高到78.38%.采用元素分析、紫外-可见光谱和红外光谱等对水解反应制备的再生腐植酸结构组成进行了表征.结果表明:再生腐植酸官能团组成与原生腐植酸官能团组成相似,但再生腐植酸的氧含量较低,酸性基团以酚羟基为主,羧基含量较少;原生腐植酸的分子质量比再生腐植酸的分子质量大,但再生腐植酸芳香核上的取代基团数量更多.

With NaOH as catalyst,humic acids were prepared by degrading the macromolecular structure of lignite using hydrolysis reaction,and the effects of temperature,ρ(NaOH),reaction time and V(water)∶m(coal)on the yield of humic acids were researched.The results show that the hydrolysis reaction can greatly improve the yield of humic acids from 11.25% to 78.38% by optimizing the hydrolysis conditions.The structure characteristics of humic acids were investigated by means of ultimate analysis,UV-Vis spectra and FTIR spectra.The results indicate that the type of functional groups are similar in both kinds of humic acids.The phenolic hydroxyl groups are the primary acidic functional groups,and the carboxyl group content of original humic acids is higher than that of regenerated humic acids.Compared with regenerated humic acids,the molecular weight of original humic acids is higher,but there are more substituents on the aromatic nucleus of regenerated humic acids.